Citation and License

Nutrition Journal 2008, 7:5
doi:10.1186/1475-2891-7-5

Published: 29 January 2008

Abstract

Background

Excess body fat is a major risk factor for disease primarily due to its endocrine
activity. In recent years several criteria have been introduced to evaluate this factor.
Nevertheless, treatment need is currently assessed only on the basis of an individual's
Body Mass Index (BMI), calculated as body weight (in kg) divided by height in m2. The aim of our study was to determine whether application of the BMI, compared to
adiposity-based criteria, results in underestimation of the number of subjects needing
lifestyle intervention.

Methods

We compared treatment need based on BMI classification with four adiposity-based criteria:
percentage body fat (%BF), considered both alone and in relation to metabolic syndrome
risk (MS), waist circumference (WC), as an index of abdominal fat, and Body Fat Mass
Index (BFMI, calculated as fat mass in kg divided by height in m2) in 63 volunteers (23 men and 40 women, aged 20 – 65 years).

Results

According to the classification based on BMI, 6.3% of subjects were underweight, 52.4%
were normal weight, 30.2% were overweight, and 11.1% were obese. Agreement between
the BMI categories and the other classification criteria categories varied; the most
notable discrepancy emerged in the underweight and overweight categories. BMI compared
to almost all of the other adiposity-based criteria, identified a lower percentage
of subjects for whom treatment would be recommended. In particular, the proportion
of subjects for whom clinicians would strongly recommend weight loss on the basis
of their BMI (11.1%) was significantly lower than those identified according to WC
(25.4%, p = 0.004), %BF (28.6%, p = 0.003), and MS (33.9%, p = 0.002).

Conclusion

The use of the BMI alone, as opposed to an assessment based on body composition, to
identify individuals needing lifestyle intervention may lead to unfortunate misclassifications.
Population-specific data on the relationships between body composition, morbidity,
and mortality are needed to improve the diagnosis and treatment of at-risk individuals.